5.15-stable review patch. If anyone has any objections, please let me know.
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From: Mauro Carvalho Chehab mchehab+huawei@kernel.org
commit ba9cf6b430433e57bfc8072364e944b7c0eca2a4 upstream.
As pointed by Coverity, there is a hidden overflow condition there. As date is signed and u8 is unsigned, doing:
date = (data[0] << 24)
With a value bigger than 07f will make all upper bits of date 0xffffffff. This can be demonstrated with this small code:
<code> typedef int64_t time64_t; typedef uint8_t u8;
int main(void) { u8 data[] = { 0xde ,0xad , 0xbe, 0xef }; time64_t date;
date = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]; printf("Invalid data = 0x%08lx\n", date);
date = ((unsigned)data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]; printf("Expected data = 0x%08lx\n", date);
return 0; } </code>
Fix it by converting the upper bit calculation to unsigned.
Fixes: cea28e7a55e7 ("media: pulse8-cec: reorganize function order") Cc: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/cec/usb/pulse8/pulse8-cec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/cec/usb/pulse8/pulse8-cec.c +++ b/drivers/media/cec/usb/pulse8/pulse8-cec.c @@ -685,7 +685,7 @@ static int pulse8_setup(struct pulse8 *p err = pulse8_send_and_wait(pulse8, cmd, 1, cmd[0], 4); if (err) return err; - date = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]; + date = ((unsigned)data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3]; dev_info(pulse8->dev, "Firmware build date %ptT\n", &date);
dev_dbg(pulse8->dev, "Persistent config:\n");